The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
In general, an internal combustion engine of a vehicle generates the reciprocal motion of a piston and the rotation motion of a crankshaft, so that the lubrication for the sliding surface of the moving system is required, and for this purpose, oil circulating in the engine should be provided. An oil pan is provided to store the oil.
In one form, the oil pan consists of an oil chamber which forms the inner space where the oil flowing at a certain flow rate according to the engine specification is stored, an oil pump pumping the internal oil, and a heater to heat the oil.
Therefore, the oil pan forms an oil circulation in which the oil is returned after lubricating the friction sliding surface of the engine by the operation of the oil pump, and particularly, in cold start condition of the engine, the heater raises the oil temperature to a certain level.
However, heating the entire oil in the oil chamber delays the engine oil warm-up time to reach a the desired level.
This is disadvantageous to the friction fuel efficiency of the engine in the cold start condition and CO2 emission reduction, and also causes difficulties in meeting the regulation reinforcement of the worldwide harmonized light vehicles test procedure (WLTP) in the environmental market and fuel efficiency/EM (emission) by the real driving emission (RDE).
We have discovered that in order to improve the engine friction efficiency during cold starting and starting operation of the engine, it is desired to accelerate the preheating of the engine oil, and improvement of the performance of the oil pan.
The foregoing is intended merely to aid in the understanding of the background of the present disclosure, and is not intended to mean that the present disclosure falls within the purview of the related art that is already known to those skilled in the art.